In order to reduce the oil agitation resistance and suppress generation of a useless power loss, various types of transmissions and the like mounted with a lubricating oil level adjustment device and a lubricating device for example have hitherto been proposed.
For example, a power transmission device for a vehicle disclosed in Japanese Patent Laying-Open No. 2006-307908 is mounted with a lubricating device. This vehicle power transmission device is provided with a casing for storing a gear lubricating oil in its inner bottom portion, a first catch tank for catching to store the oil carried up by a ring gear, and a second catch tank provided separately from the first catch tank for catching to store the oil carried up by a drive gear.
Further, a transfer case disclosed in Japanese Utility Model Laying-Open No. 6-14611 is mounted with a lubricating oil level adjustment device, and the transfer case includes an oil catcher on a casing inner wall on the high-speed gear side. The bottom of the catcher has a leak hole formed therein, so that the input shaft and the output shaft are sufficiently lubricated while low-speed rotations are made and, while high-speed rotations are made, the splashed-up lubricating oil is stored in the oil catcher to lower the oil level and thereby suppress over-agitation of the lubricating oil by the gear.
In a crankcase lubricating structure for a V-type internal combustion engine disclosed in Japanese Patent Laying-Open No. 2007-92742, an oil that have collected in a bottom portion of a crankcase is discharged by means of movements of a connecting rod.